Magmatism of the Weddell Sea rift system in Antarctica: Implications for the age and mechanism of rifting and early stage Gondwana breakup
Thick (∼800 m) basaltic successions from the eastern Antarctic Peninsula have been dated in the interval 180 – 177 Ma and preserve a transition from a continental margin arc to a back-arc extensional setting. Amygdaloidal basalts from the Black Coast region of the eastern margin of the Antarctic Pen...
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2020
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Online Access: | http://nora.nerc.ac.uk/id/eprint/522732/ https://nora.nerc.ac.uk/id/eprint/522732/1/Riley%20et%20al_Godwana%20Research.pdf https://www.sciencedirect.com/science/article/pii/S1342937X19302795 |
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ftnerc:oai:nora.nerc.ac.uk:522732 2023-05-15T13:41:43+02:00 Magmatism of the Weddell Sea rift system in Antarctica: Implications for the age and mechanism of rifting and early stage Gondwana breakup Riley, Teal Jordan, Tom Leat, Philip Curtis, Mike L. Millar, Ian 2020-03 text http://nora.nerc.ac.uk/id/eprint/522732/ https://nora.nerc.ac.uk/id/eprint/522732/1/Riley%20et%20al_Godwana%20Research.pdf https://www.sciencedirect.com/science/article/pii/S1342937X19302795 en eng Elsevier https://nora.nerc.ac.uk/id/eprint/522732/1/Riley%20et%20al_Godwana%20Research.pdf Riley, Teal orcid:0000-0002-3333-5021 Jordan, Tom orcid:0000-0003-2780-1986 Leat, Philip; Curtis, Mike L.; Millar, Ian. 2020 Magmatism of the Weddell Sea rift system in Antarctica: Implications for the age and mechanism of rifting and early stage Gondwana breakup. Gondwana Research, 79. 185-196. https://doi.org/10.1016/j.gr.2019.09.014 <https://doi.org/10.1016/j.gr.2019.09.014> cc_by_nc_nd_4 CC-BY-NC-ND Publication - Article PeerReviewed 2020 ftnerc https://doi.org/10.1016/j.gr.2019.09.014 2023-02-04T19:48:01Z Thick (∼800 m) basaltic successions from the eastern Antarctic Peninsula have been dated in the interval 180 – 177 Ma and preserve a transition from a continental margin arc to a back-arc extensional setting. Amygdaloidal basalts from the Black Coast region of the eastern margin of the Antarctic Peninsula represent a rare onshore example of magmatism associated with back-arc extension that defines the early phase of Weddell Sea rifting and magmatism, and Gondwana breakup. The early phase of extension in the Weddell Sea rift system has previously been interpreted to be related to back-arc basin development with associated magnetic anomalies attributed to mafic-intermediate magmatism, but with no clearly defined evidence of back-arc magmatism. The analysis provided here identifies the first geochemical evidence of a transition from arc-like basalts to the development of depleted back-arc basin basalts in the interval 180 – 177 Ma. The exposed Black Coast basaltic successions are interpreted to form a minor component of magmatism that is also defined by onshore sub-ice magnetic anomalies, as well as the extensive magnetic anomalies of the southern Weddell Sea. Back-arc magmatism is also preserved on the Falkland Plateau where intrusions postdating 180 Ma are associated with early phase rifting in the Weddell Sea rift system. Back-arc extension was probably short-lived and had ceased by the time the northern Weddell Sea magmatism was emplaced (<175 Ma) and certainly by 171 Ma, when an episode of silicic magmatism was widespread along the eastern Antarctic Peninsula. Previous attempts to correlate mafic magmatism from the eastern Antarctic Peninsula to the Ferrar large igneous province, or, as part of a bimodal association with the Chon Aike silicic province are both dismissed based on age and geochemical criteria. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Antarctica Weddell Sea Natural Environment Research Council: NERC Open Research Archive Antarctic The Antarctic Antarctic Peninsula Weddell Sea Weddell Falkland Plateau ENVELOPE(-50.000,-50.000,-51.000,-51.000) Black Coast ENVELOPE(-62.500,-62.500,-71.500,-71.500) Gondwana Research 79 185 196 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
description |
Thick (∼800 m) basaltic successions from the eastern Antarctic Peninsula have been dated in the interval 180 – 177 Ma and preserve a transition from a continental margin arc to a back-arc extensional setting. Amygdaloidal basalts from the Black Coast region of the eastern margin of the Antarctic Peninsula represent a rare onshore example of magmatism associated with back-arc extension that defines the early phase of Weddell Sea rifting and magmatism, and Gondwana breakup. The early phase of extension in the Weddell Sea rift system has previously been interpreted to be related to back-arc basin development with associated magnetic anomalies attributed to mafic-intermediate magmatism, but with no clearly defined evidence of back-arc magmatism. The analysis provided here identifies the first geochemical evidence of a transition from arc-like basalts to the development of depleted back-arc basin basalts in the interval 180 – 177 Ma. The exposed Black Coast basaltic successions are interpreted to form a minor component of magmatism that is also defined by onshore sub-ice magnetic anomalies, as well as the extensive magnetic anomalies of the southern Weddell Sea. Back-arc magmatism is also preserved on the Falkland Plateau where intrusions postdating 180 Ma are associated with early phase rifting in the Weddell Sea rift system. Back-arc extension was probably short-lived and had ceased by the time the northern Weddell Sea magmatism was emplaced (<175 Ma) and certainly by 171 Ma, when an episode of silicic magmatism was widespread along the eastern Antarctic Peninsula. Previous attempts to correlate mafic magmatism from the eastern Antarctic Peninsula to the Ferrar large igneous province, or, as part of a bimodal association with the Chon Aike silicic province are both dismissed based on age and geochemical criteria. |
format |
Article in Journal/Newspaper |
author |
Riley, Teal Jordan, Tom Leat, Philip Curtis, Mike L. Millar, Ian |
spellingShingle |
Riley, Teal Jordan, Tom Leat, Philip Curtis, Mike L. Millar, Ian Magmatism of the Weddell Sea rift system in Antarctica: Implications for the age and mechanism of rifting and early stage Gondwana breakup |
author_facet |
Riley, Teal Jordan, Tom Leat, Philip Curtis, Mike L. Millar, Ian |
author_sort |
Riley, Teal |
title |
Magmatism of the Weddell Sea rift system in Antarctica: Implications for the age and mechanism of rifting and early stage Gondwana breakup |
title_short |
Magmatism of the Weddell Sea rift system in Antarctica: Implications for the age and mechanism of rifting and early stage Gondwana breakup |
title_full |
Magmatism of the Weddell Sea rift system in Antarctica: Implications for the age and mechanism of rifting and early stage Gondwana breakup |
title_fullStr |
Magmatism of the Weddell Sea rift system in Antarctica: Implications for the age and mechanism of rifting and early stage Gondwana breakup |
title_full_unstemmed |
Magmatism of the Weddell Sea rift system in Antarctica: Implications for the age and mechanism of rifting and early stage Gondwana breakup |
title_sort |
magmatism of the weddell sea rift system in antarctica: implications for the age and mechanism of rifting and early stage gondwana breakup |
publisher |
Elsevier |
publishDate |
2020 |
url |
http://nora.nerc.ac.uk/id/eprint/522732/ https://nora.nerc.ac.uk/id/eprint/522732/1/Riley%20et%20al_Godwana%20Research.pdf https://www.sciencedirect.com/science/article/pii/S1342937X19302795 |
long_lat |
ENVELOPE(-50.000,-50.000,-51.000,-51.000) ENVELOPE(-62.500,-62.500,-71.500,-71.500) |
geographic |
Antarctic The Antarctic Antarctic Peninsula Weddell Sea Weddell Falkland Plateau Black Coast |
geographic_facet |
Antarctic The Antarctic Antarctic Peninsula Weddell Sea Weddell Falkland Plateau Black Coast |
genre |
Antarc* Antarctic Antarctic Peninsula Antarctica Weddell Sea |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Antarctica Weddell Sea |
op_relation |
https://nora.nerc.ac.uk/id/eprint/522732/1/Riley%20et%20al_Godwana%20Research.pdf Riley, Teal orcid:0000-0002-3333-5021 Jordan, Tom orcid:0000-0003-2780-1986 Leat, Philip; Curtis, Mike L.; Millar, Ian. 2020 Magmatism of the Weddell Sea rift system in Antarctica: Implications for the age and mechanism of rifting and early stage Gondwana breakup. Gondwana Research, 79. 185-196. https://doi.org/10.1016/j.gr.2019.09.014 <https://doi.org/10.1016/j.gr.2019.09.014> |
op_rights |
cc_by_nc_nd_4 |
op_rightsnorm |
CC-BY-NC-ND |
op_doi |
https://doi.org/10.1016/j.gr.2019.09.014 |
container_title |
Gondwana Research |
container_volume |
79 |
container_start_page |
185 |
op_container_end_page |
196 |
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1766154476176015360 |